During a typical cardiac catheterization case, physicians measure many hemodynamic parameters including cardiac flows, pressures (vascular, cardiac chamber, surgical conduit). These parameters provide clinical information and also serve as inputs for various calculations. Physicians also perform these calculations under different conditions separated in time based on clinical status or perhaps following a medication change. Physicians need to be able to view baseline (normal) hemodynamic parameters and also view how these parameters are affected by changes or by spontaneous events (such as an ECG rhythm change). Therefore, sets of parameters are grouped into “conditions”. A physician may desire to “re-use” certain parameters by copying these parameters across conditions. An example of this would be “re-using” the cardiac output from a “baseline” condition for use in a “post 100% oxygen administration” condition in order to calculate a valve area in this later condition assuming that the cardiac output stays relatively consistent throughout the time period concerned.
A user needs to be able to quickly and easily understand and troubleshoot clinical information, calculation formulae and computation constants used in calculations. Known systems typically display one pressure measurement per anatomical site, per condition. If more than one pressure measurement per anatomical site, per condition is measured, the system replaces the previous measurement with a new measurement for display and for use in calculations. Therefore, users often switch to a different condition so they can mitigate this limitation. Unfortunately, conditions are created not for the primary reason of segregating clinical states, but instead so that multiple same-site pressures can be measured and documented. As a typical example, a user obtains a patient aortic “baseline” pressure. A user measures patient LV-AO (left ventricular and ascending aortic) pullback pressures and an AO portion of the LV-AO pullback pressure overwrites an initial baseline AO pressure. At the end of the case, the user measures a patient ending AO pressure. So the user uses three different conditions (corresponding to baseline, intermediate and ending pressures) to make sure AO pressures are not over-written.
Known patient monitoring and analysis systems typically do not allow a user to select which input parameter is used in performing particular clinical calculations. If a patient aortic mean pressure is used in calculating a derived calculation of systemic vascular resistance and there are multiple aortic pressures, known systems need to provide the user with some method to select which aortic pressure to use in the calculation (now that there are multiple measurements possible). In known patient monitoring systems, the parameters exist as primary measurements such as pressures and oximetric measurements. Calculations (of resistances, shunt flows, stroke work, valve areas), use the primary measurements as inputs in order to perform calculations. Further, the calculations also often require other inputs such as patient height, weight, heart rate, and constants. Furthermore, a vascular system comprises two circuits in series therefore many of the derived calculations use parameters that measure the flows, resistances and pressures of these circuits much as Ohm's Law parameters are measured within an electrical circuit. In addition, structures of the heart such as walls are assessed by measuring the ventricular pressures, flows, ventricular stroke work and ventricular stroke power.
The heart valves are assessed visually and by valve area measurements for stenosis. The valves can also have incompetence and stenosis concurrently. The heart is also assessed for various types of uncompensated and compensated left, right or combination heart failure as well as systolic and diastolic heart failure. Occasionally, provocative measures are used to examine the severity of disease. A system according to invention principles addresses these tasks, deficiencies and needs and related problems.